Ceryle rudis
pied kingfisher

Pied kingfishers (Ceryle rudis) occur in sub-saharan African, the Middle East, the Asia mainland, and southern China. They are common in sub-saharan Africa, along the Nile, and east Egypt. In Pakistan, they are widely distributed across Punjab and the Sind plains. They are rare in Cyprus, Greece, and Poland. (Cramp et al., 1988; Rayner, Norberg, and Brooke, 1991; Roberts, 1991)

Pied kingfishers live along streams, lakes, rivers, estuaries, irrigation ditches, canals, bays, floodlands, and reedy inlets. Near mountainous areas, they live in lower river valleys. They usually avoid mangroves and large swamps. The habitat of C. rudis ranges from seashores up to 2,500 m above sea level. They are less abundant near fast flowing waters. (Cramp et al., 1988; Fry and Fry, 1992; Rayner, Norberg, and Brooke, 1991; Roberts, 1991)

One study shows that there is a distinct difference in habitat use between males and females. Females are more common in rocky shores and are less abundant in beach shorelines which primarily results from breeding patterns. Along rocky shorelines, nests are built closer to the shore. Since females spend more time incubating eggs than males, they have more access to the shore if nest sites are closer to the shoreline. (Johnston, 1989)

Ceryle rudis is a medium-sized kingfisher and has the distinctive kingfisher body type, with a large head, small body, small feet, and long, dagger-like bill. They have distinctive black and white coloration, spotted on the wings, and with a black crown on the head. (Johnston, 1989; Kemp, 2002; Line, 1995)

There are no size differences between male and female birds. The average male is 82.4 g with a bill length of 48.8 mm, and the average female is 86.4 g with a bill length of 48.4 mm. Body mass ranges from 70 to 100 g. Sexes can be distinguished by sexually dimorphic bands across the chest. Males characteristically have two black bands whereas females have only one. The typical body length is 25 to 29 cm, wing length is 13.3 to 14.2 cm, and tail length is 6.6 to 7.4 cm (Cramp et al., 1988; Johnston, 1989; Kemp, 2002; Maclean, 1985)

Young pied kingfishers are similar to adult females, but with the lores, chin, throat, and breast feathers tipped with brown. The bill is shorter and the breast band is greyish black. (Cramp et al., 1988)

Four subspecies of C. rudis have been recognized. These include C. r. rudis, C. r.travancoreensis, C .r. leucoelanura, and C.r.insignis. The geographic range of C. r. rudis consists of sub-saharan Africa, the Nile valley, southern Turkey, and Israel. The geographic range of C. r. travancoreensis is southwest India. These subspecies can be distinguished because C. r. travancoreensis has blacker upper feathers and smaller white spots than C. r. rudis, and its bill can be up to 10 mm longer. Ceryle rudis leucoelanura is similar to C. r. travancoreensis but is smaller and with lighter black spots. It occurs throughout the rest of India, Sri Lanka, northeast Afghanistan, and the Kashmir and Himalayan mountains of India and China. The remaining sub-species, C. r. insignis, is found in Hong Kong, Hainan, and China. It is similar to C. r. leucoelanura but the bill is about 5 mm longer on average. (Fry and Fry, 1992)

Pied kingfishers may be confused with crested kingfishers (Megaceryle lugubris), also called greater pied kingfishers. Crested kingfishers, unlike pied kingfishers, have a pink brown lining on the wings instead of a white lining. They are also much larger than pied kingfishers. (Fry and Fry, 1992)

Little is known about the lifespan of pied kingfishers, but their mortality increases as a result of human interference. Water pollution or changes in water habitat reduces the number of nesting sites for kingfishers and nestlings can die from flooding of the nest. Also, bioaccumulation of pollution and toxins in fish affects the mortality rates of kingfishers. Kingfishers have relatively high reproduction rates, compensating for increased mortality in some areas. (Fioratti, 1992; Rayner, Norberg, and Brooke, 1991)

Pied kingfishers are gregarious, tame, and conspicuous. They perche on the sides of streams on waterside vegetation to conserve energy. They also perch on manmade objects such as fences, canoes, and huts. Ceryle rudis creates communal roosts at certain times of year, and are the largest birds able to hover for a sustained period of time. (Cramp et al., 1988; Kemp, 2002; Maclean, 1985; Rayner, Norberg, and Brooke, 1991)

Characterist behaviors include the exhibition of a regular bobbing of the head or tail. They bathe by repeatedly diving into water, fly without undulation, and rarely hunt on land. Noisy chirps are uttered in flight or to mark territory during nesting. Individuals live in pairs or loosely tied families. They do not migrate. (Cramp et al., 1988; Kemp, 2002; Rayner, Norberg, and Brooke, 1991)

Home Range

There is little known about the home range of C. rudis, but on average 9 to 16 birds can coexist on 1 km of shoreline. They hunt for food and forage within 50 m of water. (Cramp et al., 1988)

Kingfishers have a specialized vision system for detecting movement. Kingfishers are also able to see a wide angle of view, which helps with watching for prey. They have excellent color vision and can see into the ultraviolet range. (Kemp, 2002)

Vocalizations are varied and important for declaring territory and attracting mates, so C. rudis is often heard before it is seen. They are most noisy when performing courtship dances. During dances they will make a repeated “werk……werkwerkwerk” noise. Other calls include anxiety calls, a low pitch “jerp,” and threat calls, a staccato “chikerkerker….” (Cramp et al., 1988; Fry and Fry, 1992; Roberts, 1991)

Pied kingfishers primarily eat fish. Unlike other kingfishers, pied kingfishers swallow their fish in flight after plunging. This mode of ingestion makes it difficult to identify species eaten by the kingfisher, but observed prey include Cyrtocara eucinostomus, Cichlid species, Pseudotropheus zebra, Engraulicypris argenteus, Haplochromis species, Barbus species, Gilchristella aestuarius, Ambassis nataalensis, and Hyporhamphus knysnaensis. Pied kingfishers may also take aquatic insects, crustaceans, and ,more rarely, amphibians and mollusks. Adults will regurgitate three to four pellets of undigested bones per day, but hatchlings will digest most of the bones and regurgitate only one pellet per day, absorbing more calcium to support their own bone growth. (Cramp et al., 1988; Johnston, 1989)

There are 3 foraging behaviors displayed by C. rudis: hover-plunge, perch-plunge, and skimming. Hover-plunge occurs when a bird leaves a perch and progressively flies to lower and lower heights until it finally plunges into the water to pierce the prey. Perch-plunge is a tactic in which the bird sits on a perch waiting for a fish to swim close enough so that it can plunge directly into the water after a fish. With this method, a bird will increase its perch height with an increased depth of water. A skimming bird will fly close to the water about 100 m offshore, but little is known about this process because it is difficult to gather data on this hunting method. Still, this method makes pied kingfishers unique because they are the only species of kingfisher that will forage offshore. Pied kingfisher families have been seen to perch together when fishing, but these family units will often split up. Capture success rate is only 9 to 50%. More successful plunges usually take half the time of unsuccessful plunges. (Cramp et al., 1988; Johnston, 1989)

Environmental conditions affect which type of fishing behavior birds use. In windier conditions, C. rudis will use hover-plunge 80% of the time and perch-plunge 20% of the time. In calm conditions, these statistics reverse. Perch availability is also a limiting resource. Pied kingfishers usually implement perch-plunge along a rocky shore or where many perches are available. Hover-Plunge, on the other hand is more common on sandy beaches. (Cramp et al., 1988; Johnston, 1989)

Pied kingfishers can compensate for the refraction index of water by increasing their acceleration and dive angle as the depth of the prey increases. Their nictitating membrane helps to protect their eyes from the water as they enter at high speeds. (Rayner, Norberg, and Brooke, 1991)

Food specialization reduces competition between pied kingfishers and other species. Each species of bird eats a different size fish and larger birds perch on higher spots. This allows many types of fish-eating bird species to exist in the same territory by lowering competition for food resources and perching spots. (Line, 1995)

Pied kingfishers are preyed upon by lanner falcons (Falco biarmicus). Both adults and young are preyed on by the cobras (Naja) and mongooses Herpestes. Nestlings are preyed on by safari ants (Dorylus nigricans), snakes, and small, predatory mammals. Defense of the nest involves threat displays such as half raising the wings, fanning the tail, and loud, vigorous vocalizations. Also, entire colonies will attack predators which try to enter nests. (Cramp et al., 1988; Rayner, Norberg, and Brooke, 1991)

Pied kingfishers are major predators of fish. There is some evidence for a mutualistic relationship with clawless otters (Amblonyx). (Fioratti, 1992; Maclean, 1985)

Pied kingfishers may interfere with fishing operations, including angling, fish stocking, or fish farming. (Rayner, Norberg, and Brooke, 1991)

In Nigeria, pied kingfishers are kept as pets and become tame after one week. They are free to roam with children after that time but some return to the wild. Some pied kingfishers are eaten in this area as well. (Fry and Fry, 1992)

Pied kingfishers are not currently threatened. They are rather abundant and are the most common species of kingfisher throughout their range. Although they may benefit from human dams and fish farming, they are at risk of poisoning through bioaccumulation of pollution and toxins in their fish prey. (Rayner, Norberg, and Brooke, 1991)